United Airlines flights were delayed for hours Thursday morning when computers went down for the third time this year. / Justin Sullivan Getty Images

by Nancy Trejos, USA TODAY

by Nancy Trejos, USA TODAY

UPDATE: United Airlines' computers are now up and running after malfunctioning this morning and causing delays for thousands of passengers.

"We're up and running. Getting back to normal," United spokesman Charles Hobart e-mailed to Today in the Sky late morning.

In an interview this afternoon, Hobart said that the problem had to do with an outage of the dispatch system that enables communication with aircraft on the ground before departure. Information involving baggage, cargo, weight, balance, and other operational issues is sent over that system.

It did not affect United's website. People could still check in for flights and book new flights, he said.

Hobart said the outage began at 8:30 am East Coast time. It lasted about two hours and affected "fewer than 200 flights."

Most of the affected flights were on the East Coast and the Central time zone.

Few flights had to be canceled, he said. There were also few residual effects because of the outage and operations returned to normal quickly, Hobart said.

Customers who were delayed for at least two hours can change their flights without paying the usual change fee. They also have the option to cancel and get a full refund, he said.

Judd Shapiro of Nashua, N.H., told the Associated Press that when he got to his flight's gate at Logan Airport in Boston, agents told him and other fliers that planes could land but not take off.

"JetBlue is taking off, American is taking off, but United is on the ground," he told the AP. "I was having a flawless airport experience until I got to the gate."

Travis Robertson e-mailed Today in the Sky around 11 a.m. saying that he was about to board his flight from Calgary to Chicago's O'Hare Airport. He did not expect to make his connection to Baltimore, but this afternoon emailed to say that he had made it only because his connecting flight was also delayed. Gate agents were asking four flyers to volunteer to get bumped to a later flight, he said.

"Happily boarding flight at O'Hare for Baltimore for DC with some exhausted, patient passengers," he wrote before boarding his connecting flight around 3:30 p.m.. "Things seem back in order."

This is the third computer outage United has had since June. In March, the Chicago-based United, which merged with Continental Airlines, switched to Continental's computer system, causing problems for passengers for several days.

Hobart said the latest incident was unrelated to the previous two and that it also had nothing to do with the computer system changeover.